ABSTRACT Population Science in the Pacific (PSP) is a population research program in UHCC, with an emphasis on cancer epidemiology and cancer prevention. The mission of PSP is to conduct cancer research in the populations of Hawai?i and the Pacific to identify host, lifestyle and behavioral factors associated with cancer risk and outcome, and to use this knowledge to develop intervention for cancer prevention and improvement of patient survival. The Program has 28 full members and 12 associate members. The majority of members are located in UHCC and several UH professional schools, with a few from research institutions in the Pacific. Currently, PSP research is supported by $6.82M of peer-reviewed extramural funding (direct cost), including $4.7M from PSP members based at UHCC. Over the past 5 years, PSP members published 788 cancer-related research articles, and 40% of the publications were based on the studies through intra-programmatic collaboration while 11% were inter-programmatic. Inter-institution collaboration was 90%. To achieve the Program goal, PSP members conduct cancer research under three interconnected themes. Theme 1 is to understand what lifestyle; behavioral and environmental factors are associated with cancer risk. Theme 2 is to investigate genetic susceptibility and gene-environmental interaction in cancer and identify biomarkers involved in cancer initiation and progression. Theme 3 is to develop lifestyle and behavioral interventions to reduce cancer risk and to improve patient survival. These research themes build on our overarching hypothesis that cancer is a complex disease caused by the combination of many exogenous and endogenous factors coming from our environment, genetics, lifestyles and behaviors. These factors differ substantially by race and ethnicity, and may explain most of the racial/ethnic differences in cancer incidence and mortality. Many ethnic minorities reside in Hawai?i and the Pacific with distinct lifestyle and culture. This provides a unique opportunity to study race-specific cancer etiology in these populations and develop ethnicity-tailored intervention to address their cancer burden and health disparity. Over the years, we have investigated cancer risk and outcome in relation to ethnicity-specific lifestyles, including diet, nutrient intake, dietary pattern, physical activity, obesity, tobacco smoking, substance use, and social and behavioral attributes. We have conducted many large consortial studies to investigate genetic susceptibility and gene-environment interaction in cancer. We have also developed several Hawai?i- specific or ethnicity-tailored intervention programs to reduce cancer risk or prolong patient survival. Our efforts on community outreach and information dissemination are also relentless with specific targets and goals. In the next period of CCSG support, we will continue to conduct cutting-edge research under the 3 themes, expand our research to new emerging areas such as e-cigarette, cancer metabolomics and microbiome, and continue our efforts in translating clinical and epidemiological findings into interventions for cancer prevention and elimination of disparities.